BACKGROUND: Melasma is a common cause of facial hyperpigmentation with significant cosmetic deformity. Many modalities of treatment are available, but none is satisfactory. AIM: This study was designed to compare the therapeutic response of melasma in Indian women to glycolic acid (GA 20-35%) versus trichloroacetic acid (TCA 10-20%) for chemical peeling. METHODS: Forty nonpregnant female patients with a minimum melasma area and severity index (MASI) of 10 were recruited in the study. After a detailed history and clinical examination under natural light, MASI was calculated and color photographs were taken of all the patients. The patients were advised to carry out a prepeel program of daily application of 12% GA cream or 0.1% tretinoin at night for 2 weeks. They were then treated with graded concentrations of 20-35% GA facial peel every 15 days in GA group and 10-20% TCA in the second group. RESULTS: Objective response to treatment evaluated by reduction in MASI scoring after 12 weeks was by 79% reduction (from 26.6 to 5.6) in GA group and by 73% reduction in TCA group (from 29.1 to 8.2) but this difference was not significant. Patients with epidermal-type melasma showed a better response to treatment than those with mixed-type melasma (P<0.05). Subjective response, as graded by the patient, showed good or very good response in 75% in GA group and 65% in TCA group. No relation of treatment response to age and duration of melasma could be established in this study. CONCLUSIONS: A prepeel program of daily application of 12% GA cream at night for 2 weeks, followed by graded increase in GA and TCA concentrations proved to be an equally effective treatment modality for epidermal and mixed melasma. There are hardly any major side effects, and regular use of sunscreens prevents chances of postpeel hyperpigmentation. GA peel is associated with fewer side effects than TCA and has the added advantage of facial rejuvenation.